Unconventional behavior of gas molecules on Fe (1 1 1)

The main contents of atmosphere are studied concerning their adsorption behavior on (1 1 1) surface of γ-Fe and carbon doped γ-Fe. Fe (1 1 1) is found to be highly reactive to all the considered gases except helium. Van der Waals (vdW) interactions, which were usually neglected previously, are found to play a crucial role in the gas adsorption behavior. The carbon impurity significantly affects the chemical bonding between these molecules and Fe (1 1 1) but has a negligible effect on the vdW contribution. These findings offer important clues for tuning the reactivity of Fe (1 1 1).